Blombos Cave and the Creativity of Early Modern Humans

Blombos Cave and the Creativity of Early Modern Humans Blombos Cave (abbreviated in the scientific literature as BBC) contains one of the longest and richest sequences of early subsistence, and technological and cultural innovations of pressure-flaking of stone tools, non-functional engraving, shell bead production, and red ochre processing by early modern humans worldwide, from occupations dated to the Middle Stone Age (MSA), 74,000-100,000 years ago. The rock shelter is located in a steep wave-cut calcrete cliff, about 300 kilometers (186 miles) east of Cape Town, South Africa. The cave is 34.5 meters (113 ft) above current sea level and 100 m (328 ft) from the Indian Ocean. Chronology The site deposits include 80 centimeters (31 inches) of a Later Stone Age deposit, an archaeologically sterile layer of aeolian (windblown) dune sand, called the Hiatus, and about 1.4 m (4.5 ft) comprising four Middle Stone Age levels. As of 2016, excavations have included an area of about 40 sqm (430 sq ft). Dates and thicknesses presented below are derived from Roberts et al. 2016: Late Stone Age, 2,000-300 years before the present (BP), ~80 cm in thicknessHiatus ~68 ka (thousand years BP), a culturally sterile sand dune which sealed the lower MSA, 5-10 cmM1 - Middle Stone Age Still Bay (64-73 ka, Marine Isotope Stage 5a/4), 6 strata, ~20 cmM2 Upper - Middle Stone Age Still Bay (77-82 ka, MIS 5b/a), 4 strata, ~20 cmM2 Lower - Middle Stone Age, 85-81 ka (MIS 5b), 5 strata, ~25 cmM3 - Middle Stone Age (94-101 ka, MIS 5c), 10 strata, 75 cm The Late Stone Age level contains a dense series of occupations within the rock shelter, characterized by ochre, bone tools, bone beads, shell pendants, and pottery. Middle Stone Age Occupations Together, the M1 and upper M2 levels at Blombos have been designated Still Bay phase, and paleoenvironmental reconstruction suggests the climate during this period fluctuated between arid and humid. Within an area of approximately 19 sqm have been found 65 hearths and 45 ash piles. The stone tools from the Still Bay occupations are primarily made from locally available silcrete, but also include quartzite and quartz. Nearly 400 Still Bay type points have been recovered so far, and about half of them were heat-treated and finished using sophisticated pressure flaking techniques: prior to the discoveries at BBC, pressure flaking was thought to have been invented in Upper Paleolithic Europe, only 20,000 years ago. Over 40 bone tools have been recovered, most of which are awls. A few were polished and may have been hafted as projectile points. Symbolic Behavior More than 2,000 pieces of ochre have been found so far from the Still Bay occupations, including two with deliberately engraved cross-hatched patterns from M1, and six more from M2 upper. A bone fragment was also marked, with 8 parallel lines. Over 65 beads have been discovered in the MSA levels, all of which are tick shells, Nassarius kraussianus, and most of them have been carefully perforated, polished, and in some cases deliberately heat-treated to a dark-grey to black coloration (dErrico and colleagues 2015). Vanhaeren et al. conducted experimental reproduction and close analysis of the usewear on the tick shell beads from M1. They determined that a cluster of 24 perforated shells were probably strung together in a ~10 cm long string in such a way so that they hung in alternate positions, creating a visual pattern of symmetrical pairs. A second later pattern was also identified, apparently created by knotting cords together to create floating pairs of dorsally joined shells. Each of these patterns of stringing was repeated on at least five different beadwork pieces. A discussion of the significance of shell beads may be found in Shell Beads and Behavioral Modernity. Before Still Bay The M2 level at BBC was a period of fewer and shorter occupations than either earlier or later periods. The cave contained a few basin hearths and one very large hearth at this point; the artifact assemblage includes small quantities of stone tools, consisting of blades, flakes, and cores of silcrete, quartz, and quartzite. Faunal material is limited to shellfish and ostrich eggshell. In sharp contrast, occupation debris within the M3 level at BBC is far denser. So far, M3 has produced abundant lithics but no bone tools; lots of modified ochre, including eight slabs with deliberate engravings in cross-hatching, y-shaped or crenulated designs. Stone tools include objects made of exotic fine-grained materials. The animal bone assemblage from M3 includes mostly small to medium mammals such as rock hyraxes (Procavia capensis), Cape dune mole-rat (Bathyergus suillus), steenbok/grysbok (Raphicerus sp), Cape fur seal (Arctocephalus pusillus), and eland (Tragelaphus oryx). Larger animals are also represented in fewer numbers, including equids, hippopotami (Hippopotamus amphibius), rhinoceros (Rhinocerotidae), elephant (Loxodonta africana), and giant buffalo (Sycerus antiquus). Paint Pots in M3 Within the M3 levels were also found two abalone (Haliotis midae) shells located within 6 cm of one another, and interpreted as an ochre processing workshop. The cavity of each shell was filled with a red compound of ochre, crushed bone, charcoal, and tiny stone flakes. A round flat stone with use-wear marks along the edge and face was likely used to crush and mix the pigment; it fits snugly into one of the shells and was stained with red ochre and encrusted with fragments of crushed bone. One of the shells had long scratches in its nacreous surface. Although no large painted objects or walls have been found in BBC, the resulting ochre pigment was likely used as paint to decorate a surface, object or person: while cave paintings are not known from Howiesons Poort/Still Bay occupations, ochre-painted objects have been identified within several sites of the Middle Stone Age along the South African coast. Excavations have been conducted at Blombos by Christopher S. Henshilwood and colleagues since 1991 and have continued intermittently ever since. Sources Badenhorst S, Van Niekerk KL, and Henshilwood CS. 2016. Large mammal remains from the 100 KA middle stone age layers of Blombos cave, South Africa. South African Archaeological Bulletin 71(203):46-52. Botha R. 2008. Prehistoric shell beads as a window on language evolution. Language Communication 28(3):197-212. dErrico F, Vanhaeren M, Van Niekerk K, Henshilwood CS, and Erasmus RM. 2015. Assessing the Accidental Versus Deliberate Colour Modification of Shell Beads: a Case Study on Perforated Nassarius. Archaeometry 57(1):51-76.kraussianus from Blombos Cave Middle Stone Age levels Discamps E, and Henshilwood CS. 2015. Intra-Site Variability in the Still Bay Fauna at Blombos Cave: Implications for Explanatory Models of the Middle Stone Age Cultural and Technological Evolution. PLOS 10(12):e0144866.ONE Henshilwood C, DErrico F, Van Niekerk K, Coquinot Y, Jacobs Z, Lauritzen S-E, Menu M, and Garcia-Moreno R. 2011. A 100,000-Year-Old Ochre-Processing Workshop at Blombos Cave, South Africa. Science 334:219-222. Jacobs Z, Hayes EH, Roberts RG, Galbraith RF, and Henshilwood CS. 2013. An improved OSL chronology for the Still Bay layers at Blombos Cave, South Africa: further tests of single-grain dating procedures and a re-evaluation of the timing of the Still Bay industry across southern Africa. Journal of Archaeological Science 40(1):579-594. Mourre V, Villa P, and Henshilwood C. 2010. Early use of pressure flaking on lithic artifacts at Blombos Cave, South Africa. Science 330:659-662. Moyo S, Mphuthi D, Cukrowska E, Henshilwood CS, van Niekerk K, and Chimuka L. 2016. Blombos Cave: Middle Stone Age ochre differentiation through FTIR, ICP OES, ED XRF, and XRD. Quaternary International 404, Part B:20-29. Roberts P, Henshilwood CS, Van Niekerk KL, Keene P, Gledhill A, Reynard J, Badenhorst S, and Lee-Thorp J. 2016. Climate, Environment. PLoS ONE 11(7):e0157408.and Early Human Innovation: Stable Isotope and Faunal Proxy Evidence from Archaeological Sites (98-59ka) in the Southern Cape, South Africa Thompson JC, and Henshilwood CS. 2011. Taphonomic analysis of the Middle Stone Age larger mammal faunal assemblage from Blombos Cave, southern Cape, South Africa. Journal of Human Evolution 60(6):746-767. Vanhaeren M, dErrico F, van Niekerk KL, Henshilwood CS, and Erasmus RM. 2013. Thinking strings: Additional evidence for personal ornament use Journal of Human Evolution 64(6):500-517.in the Middle Stone Age at Blombos Cave, South Africa.